Product descriptions from the supplier High Capacity: 21000mAh provides extended runtime for portable devices. Long-Life Performance: 800 cycles ensure reliable use over time. Wide Temperature Range: Operates efficiently between -20°C to 60°C. Durable Construction: Li-ion 18650 cells for robust performance. Multiple Certifications: RoHS, CE, and FCC compliant for peace of mind. Free of harmful heavy metals, conforms to international environmental standards for global export.